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Abstract:

Communications system housings, assemblies, and related alignment
features and methods are disclosed. In certain embodiments,
communications cards and related assemblies and methods that include one
or more alignment features are disclosed. In certain embodiments, at
least one digital connector disposed in the communications card is
configured to engage at least one complementary digital connector to
align at least one RF connector also disposed in the communications card
with at least one complementary RF connector. In other embodiments,
printed circuit board (PCB) assemblies are disclosed that include a
moveable standoff to provide an alignment feature. In other embodiments,
distributed antenna systems and assemblies that include one or more
alignment features are disclosed. In certain embodiments, an enclosure is
provided that includes a midplane support configured to support a
midplane interface card in a datum plane for establishing at least one
connection to at least one distributed antenna system component.

Claims:

1. A communications card, comprising: a printed circuit board (PCB)
having a first end and a second end opposite the first end; at least one
radio-frequency (RF) communications component and at least one digital
communications component disposed in the PCB; at least one
radio-frequency (RF) connector disposed at the first end of the PCB and
coupled to the at least one RF communications component; and at least one
digital connector disposed at the first end of the PCB and coupled to the
at least one digital communications component; wherein the at least one
digital connector is configured to engage at least one complementary
digital connector to align the at least one RF connector with at least
one complementary RF connector, prior to the at least one RF connector
engaging the at least one complementary RF connector.

2. The communications card of claim 1, wherein the at least one RF
connector extends a first distance beyond the first end of the PCB.

3. The communications card of claim 2, wherein the at least one digital
connector extends a second distance greater than the first distance
beyond from the first end of the PCB.

4. The communications card of claim 3, wherein the difference between the
first distance and the second distance is less than 0.1 inches.

5. The communications card of claim 1, wherein the at least one
complementary digital connector is disposed in a second PCB.

6. The communications card of claim 1, wherein the at least one
complementary RF connector is disposed in a second PCB.

7. The communications card of claim 6, wherein the at least one
complementary digital connector is disposed in the second PCB.

8. The communications card of claim 1, wherein the at least one digital
connector is blind-mated with the at least one complementary digital
connector.

9. The communications card of claim 1, wherein the at least one RF
connector is blind-mated with the at least one complementary RF
connector.

10. The communications card of claim 1, wherein the communications card
is comprised of at least one of a downlink base transceiver station (BTS)
interface card (BIC), an uplink BIC, and an optical interface card (OIC).

11. The communications card of claim 1, wherein the at least one RF
communications component is configured to communicate Radio-over-Fiber
(RoF) signals.

12. A communications assembly, comprising: a communications board having
a first end and a second end opposite the first end, and further
comprising: at least one radio-frequency (RF) connector disposed at the
first end of the communications board; and at least one digital connector
disposed at the first end of the communications board; and an interface
printed circuit board (PCB) card; wherein the at least one digital
connector is configured to engage at least one complementary digital
connector disposed in the interface PCB card to align the at least one RF
connector with at least one complementary RF connector disposed in the
interface PCB card, prior to the at least one RF connector engaging the
at least one complementary RF connector.

13. The communications assembly of claim 12, wherein the at least one RF
connector extends a first distance beyond the first end of the
communications board.

14. The communications assembly of claim 13, wherein the at least one
digital connector extends a second distance greater than the first
distance beyond the first end of the communications board.

15. The communications assembly of claim 14, wherein the difference
between the first distance and the second distance is less than 0.1
inches.

16. The communications assembly of claim 12, wherein the interface PCB
card is comprised of a midplane interface card.

17. The communications assembly of claim 16, wherein the midplane
interface card is mounted to a midplane support mounted in a housing
configured to support the midplane interface card in a datum plane of the
housing.

18. The communications assembly of claim 17, further comprising at least
one alignment feature disposed in the midplane support configured to
engage the midplane interface card to align the midplane interface card
with the midplane support in at least two dimensions of the housing.

19. The communications assembly of claim 18, wherein the at least one
alignment feature is comprised of at least two alignment openings
disposed in the midplane support each configured to receive an alignment
pin.

20. The communications assembly of claim 12 provided in an antenna
equipment housing.

21. A method of aligning communication connectors disposed in a
communications card, comprising: providing a communications card having a
first end and a second end opposite the first end; initially engaging at
least one digital connector disposed at the first end of the
communications card with at least one complementary digital connector
prior to engagement of at least one radio-frequency (RF) connector
disposed at the first end of the communications card to align the at
least one RF connector with at least one complementary RF connector; and
further engaging the at least one digital connector with the at least one
RF connector aligned to the at least one complementary RF connector to
further engage the at least one RF connector with the at least one
complementary RF connector.

22. The method of claim 21, wherein the at least one RF connector extends
a first distance beyond the first end of the communications card.

23. The method of claim 22, wherein the at least one digital connector
extends a second distance greater than the first distance beyond from the
first end of the communications card.

24. The method of claim 21, wherein the at least one complementary
digital connector and the at least one complementary RF connector are
disposed in a midplane interface card.

25. The method of claim 24, further comprising mounting the midplane
interface card to a midplane support mounted in a housing configured to
support the midplane interface card in a datum plane of the housing.

26. The method of claim 25, further comprising aligning the midplane
interface card with the midplane support to align the communications card
with the midplane support and the housing when the at least one digital
connector is engaged with the at least one complementary digital
connector disposed in the midplane interface card.

27. The method of claim 21, further comprising sliding the communications
card into a housing.

28. A printed circuit board (PCB) assembly, comprising: a first PCB
including one or more first openings disposed through the first PCB, and
wherein the first PCB connects to an assembly; a second PCB including one
or more second openings disposed through the second PCB, and wherein the
second PCB connects to the assembly; and a standoff connecting the first
PCB to the second PCB, wherein the second PCB connects to the assembly
and wherein the standoff allows the first PCB to float with respect to
the second PCB to align the first PCB in the assembly prior to the first
PCB connecting to the assembly.

29. The printed circuit board of claim 28, wherein the standoff
comprises, a body; a first collar disposed in the body at a first end of
the body and inserted into a first opening among the one or more first
openings; and a second collar disposed in the body at a second end of the
body opposite the first end and inserted into a second opening among the
one or more second openings; wherein the first collar is configured to
float inside the first opening to allow the first PCB to float with
respect to the standoff and the second PCB.

30. The PCB assembly of claim 28, wherein the first collar is configured
to float inside the first opening in at least two dimensions.

31. The PCB assembly of claim 28, wherein the second collar is configured
to not float inside the second opening.

32. The PCB assembly of claim 28, wherein the one or more first openings
each have a first inner diameter (ID).

33. The PCB assembly of claim 32, wherein the first collar has a first
outer diameter (OD) less than the first ID of the one or more first
openings.

34. The PCB assembly of claim 33, wherein the second collar has a second
OD greater than the first OD of the first collar.

35. The PCB assembly of claim 32, wherein the one or more second openings
each have a second ID greater than the first ID of the one or more first
openings.

36. The PCB assembly of claim 35, wherein the second collar has a second
OD equal to the second ID of the one or more second openings.

37. The PCB assembly of claim 28, further comprising a first threaded
shaft disposed through the first collar into the body of the standoff
configured to receive a first fastener to maintain the first collar
inside the first opening.

38. The PCB assembly of claim 37, wherein the first fastener is disposed
in a collar of a second standoff engaged with the standoff.

39. The PCB assembly of claim 37, further comprising a second threaded
shaft disposed through the second collar into the body of the standoff
configured to receive a second fastener to fixedly secure the second
collar inside the second opening.

40. The PCB assembly of claim 28, further comprising a hexagonal outer
surface disposed on at least a portion of an outer surface of the body of
the standoff.

41. The PCB assembly of claim 28, wherein the first PCB is comprised of a
first optical interface card (OIC) and the second PCB is comprised of a
second OIC.

42. The PCB assembly of claim 41 inserted into a communications equipment
housing.

43. A distributed antenna system assembly, comprising: at least one first
plate including at least one first locating alignment slot; at least one
second plate connected to the at least one first plate to form an
enclosure and including at least one second locating alignment slot; and
a midplane support configured to support a midplane interface card in a
datum plane for establishing at least one connection to at least one
distributed antenna system component; wherein the midplane support
includes at least two locating tabs for engaging the at least one first
locating alignment slot and the at least one second locating alignment
slot to align the midplane support in at least two dimensions with
respect to the at least one first plate and the at least one second
plate.

44. The assembly of claim 43, wherein the at least one first locating
alignment slot is integrated in the at least one first plate and the at
least one second locating alignment slot is integrated in the at least
one second plate.

45. The assembly of claim 43, wherein the at least two locating tabs are
integrated in the midplane support.

46. The assembly of claim 43, wherein the at least one first plate is at
least one side plate and the at least one second plate is a bottom or top
plate.

47. The assembly of claim 43, wherein the at least one first plate is at
least one first side plate and the at least one second plate is at least
one second side plate.

48. The assembly of claim 43, wherein the midplane support is configured
to align a distributed antenna system component in at least two
dimensions with respect to the at least one side plate and the bottom
plate when connected to the midplane support.

49. The assembly of claim 43, further comprising at least two alignment
openings disposed in the midplane support in the datum plane each
configured to receive an alignment pin.

50. The assembly of claim 49, wherein at least two alignment openings are
configured to align with at least two alignment openings disposed in the
midplane interface card to align the midplane interface card with the
midplane support when the alignment pin is received in each of the
alignment openings of the midplane interface card with the midplane
support.

51. The assembly of claim 49, wherein the tolerance between an alignment
opening of the at least two alignment openings disposed in the midplane
support and an alignment opening of the at least two alignment openings
disposed in the midplane interface card is 0.01 inches or less.

52. The assembly of claim 53, wherein the midplane support is a printed
circuit board (PCB).

53. The assembly of claim 52, wherein the at least one distributed
antenna system component is comprised from the group consisting of a
controller, a downlink base transceiver interface, an uplink base
transceiver interface, and an optical interface.

54. The assembly of claim 43, further comprising at least one connector
disposed in the midplane interface card configured to be connected with
at least one connector disposed on a distributed antenna system
component.

55. The assembly of claim 43, further comprising a dividing plate
attached to at least one of the at least one first plate and the at least
one second plate.

[0002] This application is also related to U.S. Provisional Patent
Application Ser. No. 61/301,488 filed Feb. 4, 2010 entitled "Modular
Distributed Antenna System Equipment Housings, Assemblies, And Related
Alignment Feature," which is incorporated herein by reference in its
entirety.

[0003] This application is also related to U.S. Provisional Patent
Application Ser. No. 61/316,584 filed Mar. 23, 2010 entitled "Modular
Distributed Antenna System Equipment Housings, Assemblies, And Related
Alignment Feature," which is incorporated herein by reference in its
entirety.

[0004] This application is also related to U.S. Provisional Patent
Application Ser. No. 61/316,591 filed Mar. 23, 2010 entitled "Modular
Distributed Antenna System Equipment Housings, Assemblies, And Related
Alignment Feature," which is incorporated herein by reference in its
entirety.

[0005] This application is also related to U.S. patent application Ser.
No. ______ entitled "Optical Interface Cards, Assemblies, and Related
Methods, Suited For Installation and Use In Antenna System Equipment,"
which is incorporated herein by reference in its entirety.

BACKGROUND

[0006] 1. Field of the Disclosure

[0007] The technology of the disclosure relates generally to enclosures
for housing distributed antenna system equipment provided in a
distributed antenna system. The distributed antenna system equipment can
include optical fiber-based distributed antenna equipment for
distributing radio frequency (RF) signals over optical fiber to remote
antenna units.

[0008] 2. Technical Background

[0009] Wireless communication is rapidly growing, with ever-increasing
demands for high-speed mobile data communication. As an example,
so-called "wireless fidelity" or "WiFi" systems and wireless local area
networks (WLANs) are being deployed in many different types of areas
(e.g., coffee shops, airports, libraries, etc.). Wireless communication
systems communicate with wireless devices called "clients," which must
reside within the wireless range or "cell coverage area" in order to
communicate with an access point device.

[0010] One approach to deploying a wireless communication system involves
the use of "picocells." Picocells are radio frequency (RF) coverage
areas. Picocells can have a radius in the range from a few meters up to
twenty meters as an example. Combining a number of access point devices
creates an array of picocells that cover an area called a "picocellular
coverage area." Because the picocell covers a small area, there are
typically only a few users (clients) per picocell. This allows for
minimizing the amount of RF bandwidth shared among the wireless system
users. In this regard, head-end communication equipment can be provided
to receive incoming RF signals from a wired or wireless network. The
head-end communication equipment distributes the RF signals on a
communication downlink to remote antenna units distributed throughout a
building or facility. Client devices within range of the picocells can
receive the RF signals and can communicate RF signals back to an antenna
in the remote antenna unit, which are communicated back on a
communication uplink to the head-end communication equipment and onto the
network. The head-end communication equipment may be configured to
convert RF signals into optical fiber signals to be communicated over
optical fiber to the remote antenna units.

[0011] It may be desirable to provide a housing or enclosure for
communication equipment for a distributed antenna system that is easily
assembled. Thus, the housing or enclosure can be easily assembled in the
field. Further, it may further be desirable to provide communication
equipment for a distributed antenna system that is compatible with
expansion of picocells. Thus, it may be desirable to provide
communication equipment for a distributed antenna system that can be
easily upgraded or enhanced to support an increased number of remote
antenna units, as an example. It may be further desired to allow
technicians or other users to provide this increased support in the
field, thus making it desirable to allow equipment changes and upgrades
to easily be made in the communication equipment with ease and proper
function.

SUMMARY OF THE DETAILED DESCRIPTION

[0012] Embodiments disclosed in the detailed description include
communications equipment housings, assemblies, and related alignment
features and methods. The equipment may be distributed antenna equipment.
In one embodiment, a communications card is provided. The communications
card may be a communications card for an optical fiber-based
communications system as a non-limiting example. The communications card
in this embodiment comprises a printed circuit board (PCB) having a first
end and a second end opposite the first end. At least one radio-frequency
(RF) communications component and at least one digital communications
component are disposed in the PCB. Further, at least one radio-frequency
(RF) connector is provided and disposed at the first end of the PCB and
coupled to the at least one RF communications component. At least one
digital connector is disposed at the first end of the PCB and coupled to
the at least one digital communications component. The at least one
digital connector is configured to engage at least one complementary
digital connector to align the at least one RF connector with at least
one complementary RF connector, prior to the at least one RF connector
engaging the at least one complementary RF connector.

[0013] In another embodiment, a communications assembly is provided. The
communications assembly comprises a communications board having a first
end and a second end opposite the first end. The communications board
includes at least one radio-frequency (RF) connector disposed at the
first end of the communications board, and at least one digital connector
disposed at the first end of the communications board. The communications
assembly further comprises an interface printed circuit board (PCB) card.
The at least one digital connector is configured to engage at least one
complementary digital connector disposed in the interface PCB card to
align the at least one RF connector with at least one complementary RF
connector disposed in the interface PCB card, prior to the at least one
RF connector engaging the at least one complementary RF connector.

[0014] In another embodiment, a method of aligning communications
connectors disposed in a communications card is provided. The method
includes providing a communications card having a first end and a second
end opposite the first end. The method also includes initially engaging
at least one digital connector disposed at the first end of the
communications card with at least one complementary digital connector
prior to engagement of at least one radio-frequency (RF) connector
disposed at the first end of the communications card to align the at
least one RF connector with at least one complementary RF connector. The
method also includes further engaging the at least one digital connector
with the at least one RF connector aligned to the at least one
complementary RF connector to further engage the at least one RF
connector with the at least one complementary RF connector.

[0015] In another embodiment, a printed circuit board (PCB) assembly is
provided. The PCB assembly comprises a first PCB including one or more
first openings disposed through the first PCB, and wherein the first PCB
connects to an assembly. The PCB assembly also comprises a second PCB
including one or more second openings disposed through the second PCB,
and wherein the second PCB connects to the assembly. A standoff is also
provided in the PCB assembly that connects the first PCB to the second
PCB, wherein the second PCB connects to the assembly and wherein the
standoff allows the first PCB to float with respect to the second PCB to
align the first PCB in the assembly prior to the first PCB connecting to
the assembly.

[0016] In another embodiment, a distributed antenna system assembly is
provided that includes at least one first plate including at least one
first locating alignment slot. The enclosure also includes at least one
second plate connected to the at least one first plate to form an
enclosure, wherein the at least one second plate includes at least one
second locating alignment slot. A midplane support is also provided and
configured to support a midplane interface card in a datum plane for
establishing at least one connection to at least one distributed antenna
system component. The midplane support includes at least two integral
locating tabs for engaging the at least one first locating alignment slot
and the at least one second locating alignment slot to align the midplane
support in at least two dimensions with respect to the at least one first
plate and the at least one second plate. In this manner, when a
distributed antenna system component is alignedly attached to the
midplane support, the distributed antenna system component is also
properly aligned with the enclosure by alignment of the midplane support
to the enclosure for aligned connections.

[0017] Embodiments disclosed in the detailed description also include
modular distributed antenna system equipment housings, assemblies, and
related alignment features. In one embodiment, a modular distributed
antenna system assembly is disclosed. The assembly includes at least one
first plate including at least one first locating alignment slot. The
assembly also includes at least one second plate including at least one
locating tab. The at least one locating tab engages with the at least one
first locating alignment slot to align the at least one first plate in at
least two dimensions to the at least one second plate to form an
enclosure configured to support at least one distributed antenna system
component.

[0018] It is to be understood that both the foregoing general description
and the following detailed description present embodiments, and are
intended to provide an overview or framework for understanding the nature
and character of the disclosure. The accompanying drawings are included
to provide a further understanding, and are incorporated into and
constitute a part of this specification. The drawings illustrate various
embodiments, and together with the description serve to explain the
principles and operation of the concepts disclosed.

BRIEF DESCRIPTION OF THE FIGURES

[0019] FIG. 1 is a partially schematic cut-away diagram of an exemplary
building and building infrastructure in which a distributed antenna
system is employed;

[0020] FIG. 2 is an exemplary schematic diagram of an exemplary head-end
communications unit ("HEU") deployed in the distributed antenna system in
FIG. 1;

[0021]FIG. 3 is an exemplary distributed antenna system equipment housing
assembly ("assembly") and enclosure configured to support the HEU of FIG.
2;

[0022] FIG. 4 is an exemplary optical interface module (OIM) comprised of
a pair of optical interface cards (OIC) configured to be installed in the
distributed antenna system equipment housing assembly of FIG. 3 as part
of the HEU;

[0023] FIG. 5 is a front view of the enclosure of FIG. 3 with a midplane
interface card of the HEU of FIG. 2 installed therein;

[0024]FIG. 6 is a rear side perspective view of the enclosure of FIG. 3
with the midplane interface card of FIG. 5 installed on a midplane
support installed therein;

[0025]FIG. 7 is a close-up front, right side perspective view of the
midplane interface card of FIG. 5 installed on a midplane support
installed in the enclosure of FIG. 3;

[0026]FIG. 8 illustrates a front side of the midplane interface card of
FIG. 5 without connectors attached to the midplane interface card;

[0027] FIG. 9 illustrates a rear view of the enclosure of FIG. 3 with a
downlink base transceiver interface (BTS) card (BIC) being inserted into
the enclosure and an uplink BIC fully inserted into the enclosure and
connected to the midplane interface card disposed in the enclosure;

[0028] FIGS. 10A and 10B illustrate front and rear perspective views,
respectively, of BIC assemblies that can be inserted in the enclosure of
FIG. 3 with the BIC disposed in the assemblies connected to the midplane
interface card disposed in the enclosure of FIG. 3;

[0029] FIG. 11 illustrates a bottom view of the BIC assembly of FIGS. 10A
and 10B;

[0030] FIG. 12 illustrates a top view of the BIC assembly of FIGS. 10 and
10B installed in the enclosure of FIG. 3;

[0031]FIG. 13 is a side perspective view of the assembly of FIG. 3 with
downlink BIC connectors for the downlink BIC and uplink BIC connectors
for the uplink BIC disposed in downlink and uplink BIC connector plates,
respectively, which are attached to the front of the enclosure;

[0034] FIG. 16 is a rear side perspective view of the enclosure of FIG. 13
illustrating cables connected to the BIC connectors disposed through the
BIC connector plates routed through openings in the midplane support to
the downlink BIC and uplink BIC disposed in the enclosure;

[0035]FIG. 17 is a top view of the enclosure of FIG. 13 illustrating
cables connected to the BIC connectors disposed through the BIC connector
plates routed through openings in the midplane support to the downlink
BIC and uplink BIC disposed in the enclosure;

[0036] FIG. 18 is a front exploded perspective view of plates of the
enclosure of FIG. 3 that are assembled together in a modular fashion to
form the enclosure;

[0037] FIGS. 19A and 19B illustrate top and bottom perspective views of
the enclosure of FIG. 3;

[0038]FIG. 20 illustrates a close-up view of the engagement of the top
plate of the enclosure in FIG. 3 with a side plate and midplane support
of the enclosure of FIG. 3;

[0039]FIG. 21 illustrates a close-up view of locating tabs disposed in
the top plate of the enclosure of FIG. 3 engaged with alignment slots
disposed in the side plate of the enclosure of FIG. 3;

[0040]FIG. 22 is a side view of the OIM that can be disposed in the
enclosure of FIG. 3;

[0041] FIG. 23 is another perspective side view of the OIM that can be
disposed in the enclosure of FIG. 3;

[0042]FIG. 24 is a rear perspective view of the OIM that can be disposed
in the enclosure of FIG. 3;

[0043] FIG. 25 is a perspective view of an alignment block that secures
the OIC to an OIM plate of the OIM of FIGS. 23 and 24;

[0044] FIG. 26A is a rear perspective view the OIM of FIGS. 23 and 24
without shields installed;

[0045] FIG. 26B is a rear perspective view the OIM of FIGS. 23 and 24 with
shield plates installed;

[0046] FIG. 27 is a close-up rear view of the OIM of FIGS. 23 and 24
showing standoffs disposed between two printed circuit boards (PCBs) of
the OICs, wherein one of the PCBs is a floating PCB;

[0047]FIG. 28 is a cross-sectional side view of the PCBs of the OICs
secured to each other via the standoffs of FIG. 27 to provide one of the
OIC PCBs as a floating PCB and the other of the OIC PCBs as a fixed PCB;

[0048] FIGS. 29A and 29B are perspective views of the floating standoffs
in FIG. 27;

[0049] FIGS. 29C and 29D are side and top views, respectively, of the
standoffs of FIG. 31;

[0050]FIG. 30 is a side cross-sectional view of the standoff of FIG. 27;

[0051] FIG. 31 is a side cross-sectional view of an alternative standoff
that can be employed to secure the OIC PCBs and provide one of the OIC
PCBs as a floating PCB;

[0052] FIGS. 32A and 32B are side cross-sectional views of an alternative
standoff that can be employed to secure the OIC PCBs and shield plates
and provide one of the OIC PCBs as a floating PCB;

[0053]FIG. 33 is a side view of the assembly of FIG. 3 showing an OIC
digital connector being connected to a complementary connector disposed
in the midplane interface card to align the OIC RF connector to be
connected to the complementary RF connector disposed in the midplane
interface card;

[0054] FIG. 34 is a top perspective view of an OIC disposed in the OIM of
FIGS. 26A and 26B illustrating the extension of the OIC PCB of beyond
transmitter optical sub-assemblies (TOSAs) and receiver optical
sub-assemblies (ROSAs) disposed in the OIC PCB;

[0055] FIG. 35 is a front perspective view of the assembly and enclosure
of FIG. 3 with a cooling fan protector plate installed to protect a
cooling fan installed in the enclosure;

[0056] FIG. 36 is a side cross-sectional view of the enclosure of FIG. 35
illustrating a cooling fan duct disposed behind the cooling fan in the
enclosure to direct air drawn into the enclosure by the cooling fan into
a lower plenum of the enclosure;

[0057]FIG. 37 is an exemplary schematic diagram of air flow drawn into
the enclosure by the cooling fan through the enclosure of FIG. 35;

[0058] FIG. 38 is another side cross-sectional view of the enclosure of
FIG. 35 illustrating the directing of air through openings in a lower
plenum plate through OICs installed in the enclosure and through openings
disposed in an upper plenum plate in the enclosure;

[0059]FIG. 39 is a rear perspective view of the enclosure of FIG. 35
illustrating an air outlet from the upper plenum of the enclosure;

[0060] FIG. 40 is a rear perspective view of the enclosure of FIG. 35
illustrating the air outlet from the upper plenum of the enclosure with
the top plate of the enclosure removed and illustrating openings in the
upper plenum plate into the uplink BIC compartment of the enclosure; and

[0061] FIG. 41 is a top view of the uplink BIC with openings disposed
therein to allow air to flow from the downlink BIC to the uplink BIC
disposed above the downlink BIC in the enclosure of FIG. 35.

DETAILED DESCRIPTION

[0062] Reference will now be made in detail to the embodiments, examples
of which are illustrated in the accompanying drawings, in which some, but
not all embodiments are shown. Indeed, the concepts may be embodied in
many different forms and should not be construed as limiting herein;
rather, these embodiments are provided so that this disclosure will
satisfy applicable legal requirements. Whenever possible, like reference
numbers will be used to refer to like components or parts.

[0063] Embodiments disclosed in the detailed description include equipment
housings, assemblies, and related alignment features and methods. The
equipment may be distributed antenna equipment.

[0064] Before discussing the exemplary distributed antenna system
equipment, assemblies and enclosures and their alignment features, which
start at FIG. 3, an exemplary distributed antenna system is first
described with regard to FIGS. 1 and 2. In this regard, FIG. 1 is a
schematic diagram of a partially schematic cut-away diagram of a building
10 that generally represents any type of building in which a distributed
antenna system 12 might be deployed. The distributed antenna system 12
incorporates a head-end communications unit or head-end unit (HEU) 14 to
provide various types of communication services to coverage areas within
an infrastructure 16 of the building 10. The HEU 14 is simply an
enclosure that includes at least one communication component for the
distributed antenna system 12. For example, as discussed in more detail
below, the distributed antenna system 12 in this embodiment is an optical
fiber-based wireless communication system that is configured to receive
wireless radio frequency (RF) signals and provide the RF signals as
Radio-over-Fiber (RoF) signals to be communicated over optical fiber 18
to remote antenna units (RAUs) 20 distributed throughout the building 10.
The distributed antenna system 12 in this embodiment can be, for example,
an indoor distributed antenna system (IDAS) to provide wireless service
inside the building infrastructure 10. These wireless services can
include cellular service, wireless services such as radio frequency
identification (RFID) tracking, wireless fidelity (WiFi), local area
network (LAN), and combinations thereof, as examples.

[0065] The terms "fiber optic cables" and/or "optical fibers" include all
types of single mode and multi-mode light waveguides, including one or
more optical fibers that may be upcoated, colored, buffered, ribbonized
and/or have other organizing or protective structure in a cable such as
one or more tubes, strength members, jackets or the like. Likewise, other
types of suitable optical fibers include bend-insensitive optical fibers,
or any other expedient of a medium for transmitting light signals. An
example of a bend-insensitive optical fiber is ClearCurve® Multimode
fiber commercially available from Corning Incorporated.

[0066] With continuing reference to FIG. 1, the infrastructure 16 includes
a first (ground) floor 22, a second floor 24, and a third floor 26. The
floors 22, 24, 26 are serviced by the HEU 14 through a main distribution
frame 28 to provide a coverage area 30 in the infrastructure 16. Only the
ceilings of the floors 22, 24, 26 are shown in FIG. 1 for simplicity of
illustration. In this example embodiment, a main cable 32 has a number of
different sections that facilitate the placement of a large number of
RAUs 20 in the infrastructure 16. Each RAU 20 in turn services its own
coverage area in the coverage area 30. The main cable 32 can include, for
example, a riser section 34 that carries all of the uplink and downlink
optical fiber cables to and from the HEU 14. The main cable 32 can
include one or more multi-cable (MC) connectors adapted to connect select
downlink and uplink optical fiber cables, along with an electrical power
line, to a number of optical fiber cables 36.

[0067] In this example embodiment, an interconnect unit 38 is provided for
each floor 22, 24, and 26. The interconnect units 38 include an
individual passive fiber interconnection of optical fiber cable ports.
The optical fiber cables 36 include matching connectors. In this example
embodiment, the riser section 34 includes a total of thirty-six (36)
downlink and thirty-six (36) uplink optical fibers, while each of the six
(6) optical fiber cables 36 carries six (6) downlink and six (6) uplink
optical fibers to service six (6) RAUs 20. The number of optical fiber
cables 36 can be varied to accommodate different applications, including
the addition of second, third, etc. HEUs 14.

[0068] According to one aspect, each interconnect unit 38 can provide a
low voltage DC current to the electrical conductors in the optical fiber
cables 36 for powering the RAUs 20. For example, the interconnect units
38 can include an AC/DC transformer to transform 110V AC power that is
readily available in the infrastructure 16. In one embodiment, the
transformers supply a relatively low voltage DC current of 48V or less to
the optical fiber cables 36. An uninterrupted power supply could be
located at the interconnect units 38 and at the HEU 14 to provide
operational durability to the distributed antenna system 12. The optical
fibers utilized in the optical fiber cables 36 can be selected based upon
the type of service required for the system, and single mode and/or
multi-mode fibers may be used.

[0069] The main cable 32 enables multiple optical fiber cables 36 to be
distributed throughout the infrastructure 16 (e.g., fixed to the ceilings
or other support surfaces of each floor 22, 24 and 26) to provide the
coverage area 30 for the first, second and third floors 22, 24 and 26. In
this example embodiment, the HEU 14 is located within the infrastructure
16 (e.g., in a closet or control room), while in another example
embodiment, the HEU 14 may be located outside of the building at a remote
location. A base transceiver station (BTS) 40, which may be provided by a
second party such as cellular service provider, is connected to the HEU
14, and can be co-located or located remotely from the HEU 14. A BTS is
any station or source that provides an input signal to the HEU 14 and can
receive a return signal from the HEU 14. In a typical cellular system,
for example, a plurality of BTSs are deployed at a plurality of remote
locations to provide wireless telephone coverage. Each BTS serves a
corresponding cell and when a mobile station enters the cell, the BTS
communicates with the mobile station. Each BTS can include at least one
radio transceiver for enabling communication with one or more subscriber
units operating within the associated cell.

[0070] The HEUs 14 are host neutral systems in this embodiment which can
provide services for one or more BTSs 40 with the same infrastructure
that is not tied to any particular service provider. The HEU 14 is
connected to six (6) optical fiber cables 36 in this embodiment.

[0071] FIG. 2 is a schematic diagram of the exemplary HEU 14 provided in
the distributed antenna system 12 of FIG. 1 to provide further detail. As
illustrated therein, the HEU 14 includes a number of exemplary
distributed antenna system components. A distributed antenna system
component can be any component that supports communication for the
distributed antenna system, such as the distributed antenna system 12 of
FIG. 1. For example, a head-end controller (HEC) 42 is included that
manages the functions of the HEU 14 components and communicates with
external devices via interfaces, such as a RS-232 port 44, a Universal
Serial Bus (USB) port 46, and an Ethernet port 48, as examples. The HEU
14 can be connected to a plurality of BTSs, transceivers, etc. at BIC
connectors 50, 52. BIC connectors 50 are downlink connectors and BIC
connectors 52 are uplink connectors. Each downlink BIC connector 50 is
connected to a downlink BTS interface card (BIC) 54 located in the HEU
14, and each uplink BIC connector 52 is connected to an uplink BIC 56
also located in the HEU 14. The downlink BIC 54 is configured to receive
incoming or downlink RF signals from the BTS inputs, as illustrated in
FIG. 2, to be communicated to the RAUs 20. The uplink BIC 56 is
configured to provide outgoing or uplink RF signals from the RAUs 20 to
the BTSs as a return communication path.

[0072] The downlink BIC 54 is connected to a midplane interface card 58.
The uplink BIC 56 is also connected to the midplane interface card 58.
The downlink BIC 54 and uplink BIC 56 can be provided in printed circuit
boards (PCBs) that include connectors that can plug directly into the
midplane interface card 58. The midplane interface card 58 is also in
direct electrical communication with a plurality of optical interface
cards (OICs) 60, which are in optical and electrical communication with
the RAUs 20 via the optical fiber cables 36. The OICs 60 convert
electrical RF signals from the downlink BIC 54 to optical signals, which
are then communicated over the optical fiber cable 36 to the RAUs 20. The
OICs 60 in this embodiment support up to three (3) RAUs 20 each.

[0073] The OICs 60 can also be provided in a PCB that includes a connector
that can plug directly into the midplane interface card 58 to couple the
links in the OICs 60 to the midplane interface card 58. In this manner,
the exemplary embodiment of the HEU 14 is scalable to support up to
thirty-six (36) RAUs 20 since the HEU 14 can support up to twelve (12)
OICs 60. If less than thirty-four (34) RAUs 20 are to be supported by the
HEU 14, less than twelve OICs 60 can be included in the HEU 14 and
connected into the midplane interface card 58. An OIC 60 is needed for
every three (3) RAUs 20 supported by the HEU 14 in this embodiment. OICs
60 can also be added to the HEU 14 and connected to the midplane
interface card 58 if additional RAUs 20 are desired to be supported
beyond an initial configuration. In this manner, the number of supported
RAUs 20 by the HEU 14 is scalable and can be increased or decreased, as
needed and in the field, by simply connecting more or less OICs 60 to the
midplane interface card 58.

[0074]FIG. 3 illustrates an exemplary distributed antenna system housing
assembly 70 (referred to as "assembly 70") that may be employed to
provide an HEU, such as the HEU 14 in FIG. 2. An HEU is simply at least
one communications component provided in an enclosure or housing. As will
be described in more detail below, the assembly 70 is modular. The
assembly 70 is configured to be easily assembled in a factory or in the
field by a technician. Further, the assembly 70 supports a number of
features that allow interface cards to be easily inserted and aligned
with respect to the midplane interface card 58 to ensure that proper
connections are made with other components of the HEU 14 that form part
of the distributed antenna system, such as the distributed antenna system
12 in FIG. 1, for example. As illustrated in FIG. 3, the assembly 70
includes an enclosure 72. The enclosure 72 is comprised of a bottom plate
74 (see also, FIG. 14B) and side plates 76A, 76B. An internal cavity 80
is formed in the space formed inside the bottom plate 74 and the side
plates 76A, 76B when assembled together for locating components of the
HEU 14, such as the components illustrated in FIG. 2, for example. A top
plate 82 can also be provided and secured to the side plates 76A, 76B, as
illustrated in FIG. 6, to protect the internal cavity 80 and protect
components of the HEU 14 disposed therein. Note that only two plates can
be provided for the enclosure 72, if desired. For example, one plate
could be a first plate wherein a second plate is attached to the first
plate. The first plate could be any of the bottom plate 74, the side
plates 76A, 76B, and top plate 82. Also, the second plate could be any of
the bottom plate 74, the side plates 76A, 76B, and top plate 82.

[0075] With continuing reference to FIG. 3, the enclosure 72 is configured
to support the OICs 60 illustrated in FIG. 2. In this embodiment as
illustrated FIG. 4, the OICs 60 are grouped together in pairs to form an
optical interface module (OIM) 84. Thus, an OIM 84 is comprised of two
(2) OICs 60 that each support up to three (3) RAUs 20 and thus the OIM 84
supports up to six (6) RAUs 20 in this embodiment. As illustrated in FIG.
4, each OIC 60 is provided as a PCB 86 with integrated circuits provided
therein to provide electrical signal to optical signal conversions for
communication downlinks and vice versa for communication uplinks. An OIM
plate 88 is provided to assist in coupling a pair of OICs 60 together to
form the OIM 84. As will be discussed in more detail below in this
disclosure, the pair of OICs 60 are secured to the OIM plate 88 to form
the OIM 84. The OIM plate 88 serves to support the OIC 60 and contribute
to the alignment the OICs 60 for proper insertion into and attachment to
the enclosure 72, which in turn assists in providing for a proper and
aligned connection of the OICs 60 to the midplane interface card 58, as
shown in FIG. 3. In this embodiment, the PCBs 86 are attached to shield
plates 95A, 95B that are attached to the OIM plate 88 to provide
mechanical, RF, and other electromagnetic interference shielding.

[0076] The OICs 60 are also secured together via standoff connectors 89
that contain alignment features to allow self-alignment between the OICs
60 when connected to the midplane interface card 58, as illustrated in
FIG. 4 and as will be described in more detail in this disclosure.
Connector adapters 90 are disposed in the OIM plate 88 and provide for
optical connections of OIC PCBs 86 of the OICs 60. The connector adapters
90 are disposed through openings 92 in the OIM plate 88 to provide
external access when the OIM 84 is installed in the enclosure 72. RAUs 20
can be connected to the connector adapters 90 to establish connections to
the OICs 60 of the HEU 14, and thus provided as part of the distributed
antenna system 12, via the optical fiber cables 36 in FIG. 1 being
connected to the connector adapters 90. These connector adapters 90 may
receive any type of fiber optic connector, including but not limited to
FC, LC, SC, ST, MTP, and MPO. The OIM 84 is secured to the enclosure 72
via spring-loaded connector screws 85 disposed in the OIM plate 88 that
are configured to be inserted into apertures 87 (see FIG. 5) to secure
the OIM plate 88 to the enclosure 72, as illustrated in FIG. 3.

[0077] To provide flexibility in providing OIMs 84, the HEC 42, and the
downlink BIC 54 and uplink BIC 56 in the HEU 14, the enclosure 72
provides for the midplane interface card 58 to be disposed inside the
internal cavity 80 extending between the side plates 76A, 76B in a datum
plane 81, as illustrated in FIG. 3. As will be discussed in more detail
below, alignment features are provided in the midplane interface card 58
and the enclosure 72 such that proper alignment of the midplane interface
card 58 with the enclosure 72 is effected when the midplane interface
card 58 is inserted in the enclosure 72. Thus, when the OIMs 84, the HEC
42, and the downlink BIC 54 and uplink BIC 56 are properly and fully
inserted into the enclosure 72, the alignment between these components
and the enclosure 72 effect proper aligned connections between connectors
on these components (e.g., connectors 94) and the midplane interface card
58. Proper connection to the midplane interface card 58 is essential to
ensure proper connection to the proper components in the HEU 14 to
support communications as part of a distributed antenna system supported
by the HEU 14. Aligning these connections is important for proper
connection, especially given that the enclosure 72 is modular and
tolerances of the enclosure components in the enclosure 72 can vary.

[0078] To illustrate the alignment features to properly align the midplane
interface card 58 with the enclosure 72, FIG. 5 is provided to illustrate
a front view of the enclosure 72 with the midplane interface card 58
installed therein. FIG. 5 illustrates a front side 93 of the midplane
interface card 58. FIG. 6 illustrates a rear perspective view of the
enclosure 72 with the midplane interface card 58 installed. No HEU 14
components are yet installed in the enclosure 72 in FIG. 5. FIG. 6
illustrates channels 91A that are disposed in the bottom plate 74 of the
enclosure 72 to receive bottom portions of the HEC 42 and OIMs 84 to
align these components in the X and Y directions of the enclosure 72.
Channels 91B (FIG. 14B) are also disposed on the top plate 82 and are
aligned with the channels 91A disposed in the bottom plate 74 to receive
top portions of the HEC 42 and OIMs 84 to align these components in the X
and Y directions. It is important that the midplane interface card 58 be
properly aligned with regard to the enclosure 72 in each of the X, Y, and
Z directions, as illustrated in FIG. 5, because the midplane interface
card 58 includes connectors 94A, 94B, 94C that receive complementary
connectors (described in more detail below) from components of the HEU 14
installed in the enclosure 72.

[0079] The connectors 94A are disposed in the midplane interface card 58
and designed to accept connections from the HEC 42 and other like cards
with a compatible complementary connector, as illustrated in FIG. 3. The
connectors 94B are disposed in the midplane interface card 58 and
designed accept digital connections from the OICs 60. The RF connectors
94C are disposed in the midplane interface card 58 and designed to accept
RF connections from the OIC 60 (see element 195, FIGS. 21 and 22). The
enclosure 72 is designed such that alignment of the HEU 14 components is
effected with respect to the enclosure 72 when installed in the enclosure
72. Thus, if the connectors 94A, 94B, 94C are not properly aligned with
respect to the enclosure 72, components of the HEU 14, by their alignment
with the enclosure 72, may not be able to establish proper connections
with the midplane interface card 58 and thus will not be connected to the
distributed antenna system provided by the HEU 14.

[0080] In this regard, as illustrated in FIGS. 5 and 6, a midplane support
100 is installed in the datum plane 81 of the enclosure 72 to align the
midplane interface card 58 in the X, Y, and Z directions with regard to
the enclosure 72. The midplane support 100 may be a plate formed from the
same material as the bottom plate 74, the side plates 76A, 76B, and/or
the top plate 82. The midplane support 100 provides a surface to mount
the midplane interface card 58 in the enclosure 72. A divider plate 101
is also provided and attached to the midplane support 100, as illustrated
in FIG. 6, to separate compartments for the downlink and uplink BICs 54,
56 and a power supply 59 (FIG. 6) to provide power for the HEC 42 and
other components of the HEU 14. As will also be described in more detail
below, the modular design of the enclosure 72 is provided such that the
midplane support 100 is properly aligned in the datum plane 81 in the X,
Y, and Z directions when installed in the enclosure 72. Thus, if
alignment features are disposed in the midplane support 100 to allow the
midplane interface card 58 to be properly aligned with the midplane
support 100, the midplane interface card 58 can be properly aligned with
the enclosure 72, and as a result, the connectors of the components of
the HEU 14 installed in the enclosure 72 will be properly aligned to the
connectors 94A, 94B, 94C disposed in the midplane interface card 58.

[0081] As illustrated in FIG. 5, two alignment features 102 are disposed
in the midplane support 100 and the midplane interface card 58 to align
the midplane interface card 58 in the X, Y, and Z directions with respect
to the midplane support 100, and thus the enclosure 72. FIG. 7
illustrates a close-up view of the right-hand side of the midplane
interface card 58 installed on the midplane support 100 that also shows
one of the alignment features 102. The alignment features 102 in this
embodiment are comprised of PCB support guide pins 104 that are
configured to be disposed in alignment openings 106, 108 disposed in the
midplane interface card 58 and midplane support 100, respectively. FIG. 8
illustrates a front side 109 of the midplane interface card 58 without
connectors. The PCB support guide pins 104 are installed and configured
to be disposed through the alignment openings 106, 108. Before the PCB
support guide pins 104 can be inserted through both alignment openings
106, 108 disposed in the midplane interface card 58 and midplane support
100, the alignment openings 106, 108 are aligned with the PCB support
guide pins 104. Thus, by this alignment, the midplane interface card 58
is aligned in the X and Y directions with the midplate support 100. For
example, the inner diameter of the openings 106, 108 may be 0.003 inches
or less larger that the outer diameter of the PCB support guide pin 104.
Also, the tolerances between the center lines in the X direction of the
alignment openings 106, 108 may be less than 0.01 inches or 0.005 inches,
as examples, to provide an alignment between the alignment openings 106,
108 before the PCB support guide pins 104 can be disposed through both
alignment openings 106, 108. Any other tolerances desired can be
provided.

[0082] Once the PCB support guide pins 104 are inserted into the openings
106, 108, the midplane interface card 58 can be screwed in place to the
midplane support 100. In this regard, additional openings 110 are
disposed in the midplane interface card 58, as illustrated in FIG. 5.
These openings 110 are configured to align with openings 112 disposed in
the midplane support 100 when the alignment openings 106, 108 are aligned
or substantially aligned. A total of twenty (20) or other number of
openings 110, 112 are disposed in the midplane interface card 58 and
midplane support 100, as illustrated in FIG. 5. Fasteners 114, such as
screws for example, can be disposed through the openings 110, 112 to
secure the midplane interface card 58 to the midplane support 100 and to,
in turn, align the midplane interface card 58 to the midplane support 100
in the Z direction.

[0083]FIG. 8 illustrates the midplane interface card 58 without the
fasteners 114 disposed in the openings 110 to further illustrate the
openings 110. The fasteners 114 are screwed into self-clinching standoff.
For example, the self-clinching standoff may be disposed in the midplane
support 100. The height tolerances of the self-clinching standoffs may be
between +0.002 and -0.005 inches, as an example. The inner diameter of
the openings 110 may be 0.030 inches greater than the outer diameter of
the fasteners 114, for example, since openings 110 are not used to
provide the alignment provided by PCB support guide pins 104 and openings
106, 108. Further, as illustrated in FIG. 5, openings 115 are disposed in
the midplane support 100 to allow cabling to be extended on each side of
the midplane interface card 58. The nominal distance in one embodiment
between the midplane support 100 and the midplane interface card 58 when
installed is 0.121 inches, although any other distances could be
provided.

[0084] The midplane interface card 58 is also configured to receive direct
connections from the downlink BIC 54 and the uplink BIC 56 when installed
in the enclosure 72. As illustrated in the rear view of the enclosure 72
in FIG. 9, the downlink BIC 54 and uplink BIC 56 are designed to be
inserted through a rear side 116 of the enclosure 72. Referring back to
FIG. 8, connector holes 116A, 116B are disposed on the midplane interface
card 58 in FIG. 8 show where connectors are provided that are connected
to connectors 118 (see FIGS. 10A and 10B) of the downlink BIC 54 and
uplink BIC 56 when the downlink BIC 54 and uplink BIC 56 are received are
fully inserted into the enclosure 72. The alignment features 102, by
being provided between the midplane interface card 58 and the midplane
support 100 as previously discussed, also provide proper alignment of the
connector holes 116A, 116B to be properly aligned with the connectors 118
in the downlink BIC 54 and uplink BIC 56 when inserted in the enclosure
72.

[0085] FIGS. 10A and 10B illustrate a BIC assembly 120 that supports the
downlink BIC 54 or the uplink BIC 56 and is configured to be received in
the enclosure 72 to connect the downlink BIC 54 or the uplink BIC 56 to
the midplane interface card 58. The BIC assembly 120 is the same whether
supporting the downlink BIC 54 or the uplink BIC 56; thus, the BIC
supported by the BIC assembly 120 in FIGS. 10A and 10B could be either
the downlink BIC 54 or the uplink BIC 56. The BIC assembly 120 includes a
BIC support plate 122 that is configured to secure the downlink and
uplink BICs 54, 56. Standoffs 124 are provided to support a BIC PCB 126
of the downlink and uplink BICs 54, 56 above the BIC support plate 122. A
BIC face plate 128 is coupled generally orthogonal to the BIC support
plate 122 to secure the downlink and uplink BICs 54, 56 to the enclosure,
as illustrated in FIG. 9. Alignment features 130 are provided between the
BIC support plate 122 and the BIC face plate 128 to ensure that the BIC
PCB 126, and thus its connector 118, are properly aligned in the X and Y
directions, as illustrated in FIG. 9, when the downlink and uplink BICs
54, 56 are inserted in the enclosure 72. Thus, the connector 118 will be
properly aligned with the enclosure 72 and thus the connector holes 116A,
116B on the midplane interface card 58 to allow a proper connection
between the downlink and uplink BICs 54, 56 and the midplane interface
card 58. The alignment features 130 will ensure alignment of the BIC PCB
126 as long as the BIC PCB 126 is properly installed on the BIC support
plate 122, which will be described in more detail below. As illustrated
on the bottom side 127 of the BIC assembly 120 in FIG. 11, the alignment
features 130 in this embodiment are protrusions 132 attached to the BIC
support plate 122 that are configured to be disposed through openings 134
disposed through the BIC face plate 128, as illustrated in FIG. 10A. The
downlink or uplink BIC connectors 50, 52 (see also, FIG. 2), as the case
may be, are disposed through the BIC face plate 128 to allow BTS inputs
and outputs to be connected to the downlink and uplink BICs 54, 56,
external to the enclosure 72 when the downlink and uplink BICs 54, 56 are
fully inserted in the enclosure 72.

[0086] To provide alignment of the BIC PCB 126 to the BIC support plate
122, alignment features 140 are also disposed in the BIC PCB 126 and the
BIC support plate 122, as illustrated in FIGS. 10A, 10B, 11 and 12. As
illustrated therein, PCB support guide pins 142 are disposed through
alignment openings 144, 146 disposed in the BIC PCB 126 and BIC support
plate 122, respectively, when aligned. The alignment openings 144 and 146
are designed to only be aligned to allow the PCB support guide pin 142 to
be disposed therein when the alignment openings 144, 146 are in
alignment. For example, the tolerances between the alignment openings
144, 146 may be less than 0.01 inches or less than 0.005 inches, as
examples, to ensure an alignment between the alignment openings 144, 146
before the PCB support guide pins 142 can be disposed through both
alignment openings 144, 146. Any other tolerances desired can be
provided.

[0087] FIGS. 9-12 described above provide the BIC connectors 50, 52
disposed through the rear side 116 of the enclosure 70. To establish
connections with the BIC connectors 50, 52, connections are established
to the BIC connectors 50, 52 in the rear side 116 of the enclosure 72.
Alternatively, the enclosure 72 could be designed to allow connections to
be established to the downlink BIC 54 and the uplink BIC 76 from the
front side of the enclosure 72. In this regard, FIG. 13 is a side
perspective view of the assembly 70 of FIG. 3 with the downlink BIC
connectors 50 for the downlink BIC and the uplink BIC connectors 52 for
the uplink BIC 56 disposed through a front side 147 of the enclosure 72.
As illustrated therein, a downlink BIC connector plate 149 containing
downlink BIC connectors 50 disposed therein is disposed in the front side
147 of the assembly 70. Similarly, an uplink BIC connector plate 151
containing uplink BIC connectors 52 disposed therein is also disposed in
the front side 147 of the assembly 70.

[0088] FIGS. 14 and 15 illustrate front and rear perspective views of an
exemplary BIC connector plate, which can be BIC connector plate 149 or
151. As illustrated therein, the BIC connectors 50 or 52 are disposed
through the BIC connector plate 149 or 151 so that the BIC connectors 50
or 52 can be accessed externally through the front side 147 of the
assembly 70. Fasteners 153 can be disposed through openings 155 in the
BIC connector plates 149 or 151 to fasten the BIC connector plates 149 or
151 to the assembly 70. Channel guides 173 are attached to the BIC
connector plates 149 or 151 that are configured to be received in the
channels 91A, 91B in the assembly 70 to assist in aligning the BIC
connector plates 149 or 151 with the assembly 70 when disposing the BIC
connector plates 149 or 151 in the assembly 70. Because the downlink BIC
54 and uplink BIC 56 are disposed in the rear of the assembly 70, as
illustrated in FIGS. 9-12, the BIC connectors 50 or 52 are provided in
the BIC connector plates 149 or 151 to connect the BIC connectors 50 or
52 to the downlink BIC 54 or uplink BIC 56, as illustrated in FIG. 15 and
as will be described below with regard to FIGS. 16 and 17. Further, a BIC
ribbon connector 157 is disposed in the BIC connector plates 149 or 151
to connect to the downlink BIC 54 or uplink BIC 56 to carry status
signals regarding the downlink BIC 54 or uplink BIC 56 to be displayed on
visual indicators 161 disposed on the BIC connector plates 149 or 151.

[0089] FIG. 16 is a rear side perspective view of the enclosure 72
illustrating cables 165, 167 connected to the BIC connectors 50, 52 being
disposed through an opening 169 in the midplane support 100 and an
opening 171 in the divider plate 101. The cables 165, 167 provide
connections between the BIC connectors 50, 52 and the BIC ribbon
connector 157 so that the BIC connectors 50, 52 can be disposed in the
front side 147 of the assembly 70 with the downlink BIC 54 and the uplink
BIC 56 disposed in the rear of the assembly 70. FIG. 17 is a top view of
the assembly 70 further illustrating the routing of the cables 165, 167
connecting the BIC connectors 50, 52 and BIC ribbon connector 157 through
the openings 169, 171 to the downlink BIC 54 and uplink BIC 56.

[0090] The enclosure 72 is also provided as a modular design to allow the
enclosure to be easily assembled and to effect proper alignment between
the various plates and components that form the enclosure 72. For
example, FIG. 18 illustrates a front exploded perspective view of the
enclosure 72. As illustrated therein, the enclosure 72 is formed from the
side plates 76A, 76B being connected to and between the bottom plate 74
and the top plate 82. The midplane support 100 is configured to be
disposed in the datum plane 81 (see FIG. 5) of the enclosure 72 when
assembled. The divider plate 101 is configured to be attached to the
midplane support 100 generally orthogonal to the datum plane 81 to divide
compartments for the downlink and uplink BICs 54, 56 and a power module
disposed in the HEU 14 on the rear side of the midplane support 100.

[0091] To further illustrate the modularity and ease in assembly of the
enclosure 72, FIGS. 19A and 19B illustrate top and bottom perspective
view, respectively, of the enclosure 72 to further illustrate how the
side plates 76A, 76B are attached to the top plate 82 and bottom plate
74. In this regard, the top and bottom plates 82, 74 include an alignment
feature in the form of locating tabs 150, 152. The locating tabs 150, 152
are integrally formed in the top and bottom plates 74, 82 and are
configured to engage with complementary alignment openings or alignment
slots 154, 156 integrally disposed in the side plates 76A, 76B. FIGS. 19A
and 19B also illustrates a close-up view of the top plate 82 attached to
the side plate 76B and the locating tabs 150 engaged with the alignment
slots 154. This allows the top and bottom plates 74, 82 to be attached in
proper alignment quickly and easily with the side plates 76A, 76B when
assembling the enclosure 72. In the enclosure 72, there are four (4)
locating tabs 150, 152 on each side of the top and bottom plates 82, 74,
and four (4) complementary alignment slots 154, 156 disposed on each side
of the side plates 76A, 76B, although any number of locating tabs and
slots desired can be employed. Fasteners can then be employed, if desired
to secure the locating tabs 150, 152 within the alignment slots 154, 156
to prevent the enclosure 72 from disassembling, as illustrated in FIG.
20. FIG. 20 also illustrates a close-up view of the top plate 82 attached
to the side plate 76B in this regard.

[0092] As illustrated in FIG. 20, the top plate 82 contains rolled or bent
up sides 180 that are configured to abut tightly against and a top inside
side 182 of the side plate 76B. The same design is provided between the
top plate 82 and the side plate 76A, and the bottom plate 74 and the side
plates 76A, 76B. An outer width W1 of the top and bottom plates 82,
74 is designed such that the fit inside an inner width W2 of the
side plates 76A, 76B, as illustrated in FIG. 19A. Fasteners 184 disposed
in openings 186 in the side plates 76A, 76B and openings 188 in the top
and bottom plates 82, 74 pull the side plates 76A, 76B and the top and
bottom plates 82, 74 close together tightly to provide a tight seal
therebetween. Further, as illustrated in FIG. 20, an alignment tab 181
extending from the midplane support 100 is shown and extends into a slot
183 disposed in the top plate 82 to further align the midplane support
100 with the enclosure 72.

[0093]FIG. 21 also illustrates alignment features provided in the
midplane support 100 that are configured to align the midplane support
100 with the enclosure 72. As illustrated in FIG. 21, the top plate 82
includes integral alignment slots 160 in the datum plane 81 when the top
plate 82 is secured to the side plate 76B. The side plate 76B also
includes alignment slots 162 integrally disposed along the datum plane 81
when the side plate 76B is secured to the top plate 82. The midplane
support 100 includes locating tabs 164 that are disposed through the
alignment slots 160, 162 when the midplane support 100 is properly
aligned with the enclosure 72 and the top plate 82 and side plate 76B
(see also, FIG. 7). In this manner, as previously described, when the
midplane interface card 58 is properly aligned with the installed
midplane support 100, the midplane interface card 58 is properly aligned
with the enclosure 72 and thus any HEU 14 components installed in the
enclosure 72. Alignment slots 166 similar to alignment slots 160 are also
integrally disposed in the bottom plate 74, as illustrated in FIG. 19B.
These alignment slots 166 are also configured to receive locating tabs
168 in the midplane support 100, as illustrated in FIG. 19B, to align the
midplane support 100.

[0094] Further, as illustrated in FIGS. 19A and 19B, the enclosure 72 is
also configured to receive and support removable mounting brackets 170A,
170B to secure the enclosure 72 to an equipment rack. As illustrated
therein, the mounting brackets 170A, 170B include folded down components
that form tabs 172A, 172B. The side plate 76A, 76B include integral
alignment slots 174, 176, respectively, that are configured to receive
the tabs 172A, 172B. To secure the tabs 172A, 172B to the enclosure 72,
fasteners 178A, 178B are disposed through openings 179A, 179B in the tabs
172A, 172B, respectively, and secure to the top plate 82 and bottom plate
74.

[0095] Other features are provided to support alignment of components of
the HEU 14 and to support proper connection of these components to the
midplane interface card 58. For example, one of these components is the
OIM 84, as previously discussed. The OIM 84 is illustrated in FIG. 22,
wherein fiber routing guides 190 can be disposed on the outside of the
PCB 86 of the OIC 60 to assist in routing optical fibers 192 from
connector adapters 90 that are configured to connect to optical fibers
connected to the RAUs 20 (see FIG. 2). The optical fibers 192 are
connected to the electronic components of the OIC 60 to convert the
received optical signals from the RAUs 20 into electrical signals to be
communicated to the uplink BIC 56 via connector 194 and RF connectors 195
that are connected to the midplane interface card 58 when the OIM 84 is
inserted into the enclosure 72, as previously discussed.

[0096] As previously discussed, the OIM 84 includes two OICs 60 connected
to the OIM plate 88 to be disposed in channels 91A, 91B in the enclosure
72. Also, by providing two OICs 60 per OIM 84, it is important that the
connectors 194 are properly aligned and spaced to be compatible with the
alignment and spacing of the complementary connectors 94B in the midplane
interface card 58 (see FIG. 5). Otherwise, the OICs 60 may not be able to
be properly connected to the midplane interface card 58. For example, if
the PCBs 86 of the OICs 60 are not both secured in proper alignment to
the OIM plate 88, as illustrated in FIG. 23, one or both OICs 60 may not
be aligned properly in the Z direction.

[0097] In this regard, FIG. 24 illustrates an alignment feature 200 to
ensure that the PCBs 86 of the OICs 60 are properly secured and aligned
with regard to the OIM plate 88 in the Z direction. As illustrated in
FIG. 24 and more particularly in FIG. 25, an alignment block 202 is
provided. As illustrated in FIG. 25, the alignment block 202 includes two
alignment surfaces 204A, 204B. As illustrated in FIGS. 24 and 25,
alignment surface 204A is configured to be disposed against the surface
of the PCB 86. Alignment surface 204B is configured to be disposed
against a rear surface 206 of the OIM plate 88, as also illustrated in
FIG. 24. As illustrated in FIG. 25, guide pin 208 extends from the
alignment surface 204A that is configured to be disposed in an opening in
the PCB 86 of the OICs 60. An opening 210 disposed in the alignment
surface 204A is configured to align with an opening disposed in the PCB
86 wherein a fastener can be disposed therein and engaged with the
opening 210 to secure the PCB 86 to the alignment block 202. To align the
alignment block 202 to the PCB 86, the guide pin 208 is aligned with an
opening in the PCB 86 and inserted therein when aligned.

[0098] The alignment surface 204B also contains an opening 212 that is
configured to receive a fastener 214 (FIG. 23) disposed through the OIM
plate 88 and engage with the opening 212. Some of the fasteners 214 may
be configured to also be disposed through openings in the connector
adapters 90, as illustrated in FIG. 23, to secure both the connector
adapters 90 to the OIM plate 88 and the OIM plate 88 to the OICs 60. In
this manner, the OIM plate 88 is secured to the alignment block 202, and
the alignment block 202 is aligned and secured to the PCB 86. Thus, the
OIM plate 88 is aligned with the PCB 86 of the OIC 60 in the Z direction.

[0099] Further, when tolerances are tight, it may be difficult to ensure
proper mating of all connectors 194, 94B between the OICs 60 and the
midplane interface card 58. For example, as illustrated in FIG. 23, if
the spacing between standoffs 196 securing and spacing apart the PCBs 86
of the OICs 60 is not the same as the spacing between connectors 94B in
the midplane interface card 58, alignment of the OICs 60 in the X, Y, or
Z directions may not be proper, and thus only one or neither OIC 60 may
be able to be connected to the midplane interface card 58 and/or without
damaging the midplane interface card 58 and/or its connectors 94B.

[0100] In this regard, FIG. 26A illustrates a rear perspective view of the
OIM 84 of FIGS. 23 and 24 with standoffs 196 provided between the two
PCBs 86 of the OICs 60 that allow one PCB 86 to float with regard to the
other PCB 86. FIG. 26B illustrates a rear perspective view of the OIM 84
of FIG. 26A within optional shield plates 95A, 95B installed to the PCBs
86 and to the OIM plate 88 to provide mechanical, RF, and other
electromagnetic interference shielding. In this regard, tolerances are
eased when the OICs 60 are secured to the OIM plate 88 to allow one
connector 194 of an OIC 60 to move or float slightly in the X, Y, or Z
directions with regard to the other OIC 60, as illustrated in FIGS. 26A
and 26B. FIG. 27 illustrates a close-up view of one standoff 196 between
two PCBs 86A, 86B of the OICs 60. As will be described in more detail
below, the standoff 196 is allowed to float about the top PCB 86A to
allow the positioning or orientation of the top PCB 86A to move slightly
in the X, Y, or Z directions with regard to the bottom PCB 86B.

[0101]FIG. 28 is a side cross-sectional view of the top and bottom PCBs
86A, 86B of the OIM 84 mounted to each other with the standoff 196, as
illustrated in FIGS. 26A and 26B and 28, to further illustrate the
floating top PCB 86A. In this regard, the standoff 196 is comprised of a
body 199. The body 199 of the standoff 196 is also illustrated in the
perspective, side and top view of the standoff in FIGS. 29A-29C,
respectively. The body 199 includes a first collar 220 at a first end 222
of the body 199 of an outer diameter OD1 than is smaller than an
outer diameter OD2 of a second collar 224 located at a second end
226 of the body 199, as illustrated in FIG. 28-30. The first and second
collars 220, 224 are configured to be received within openings 228, 230
of the top and bottom PCBs 86A, 86B, as illustrated in FIG. 28. The first
end 222 and second end 226 of the body 199 contains shoulders 232, 234
that limit the amount of disposition of the first and second collars 220,
224 through the openings 228, 230 in the top and bottom PCBs 86A, 86B.

[0102] As illustrated in FIG. 28, the second collar 224 is designed so
that the outer diameter OD2 includes a tight tolerance with the
inner diameter of the opening 230. In this manner, the second collar 224
will not float within the opening 230. Further, a height H2 of the
second collar 224 (see FIG. 29C) is less than a width W3 of the PCB
86A and opening 230 disposed therein, as illustrated in FIG. 28. This
allows a head 236 of a fastener 238 to be secured directly onto the outer
surface 239 of the bottom PCB 86B when disposed through a threaded shaft
240 of the body 199 to firmly secure the standoff 196 to the bottom PCB
86B. Because of the outer diameter OD2 and height H2 provided
for the second collar 224 of the standoff 196, the bottom PCB 86B does
not float.

[0103] However, to allow the top PCB 86A to float, the outer diameter
OD1 and height H1 of the first collar 220 is different from
that of the second collar 224. In this regard, as illustrated in FIGS.
28-29C and 30, the outer diameter OD1 of the first collar 220 is
smaller than the inner diameter of the opening 228. A gap G is formed
therebetween to allow the first collar 220 to move slightly with respect
to the opening 228 when disposed therein. Further, the height H1 of
the first collar 220 is taller than the width W1 of the top PCB 86A,
as illustrated in FIG. 28. Thus when a fastener 242 is disposed within
the threaded shaft 240 and tightened, a head 244 of the fastener 242 will
rest against a top surface 246 of the first collar 220. Because the first
collar 220 extends in a plane about a top surface 248 of the top PCB 86A,
the head 244 of the fastener 242 does not contact the top surface 248 of
the PCB 86A. Thus, when the fastener 242 is tightened, a friction fit is
not provided between the head 244 and the top surface 248 of the PCB 86A,
allowing the top PCB 86A to float with respect to the standoff 196 and
the bottom PCB 86B.

[0104] FIG. 31 illustrates an alternative standoff 196' that is the same
as the standoff 196, but the thread shaft does not extend all the way
through the body 199' like the standoff 196 in FIG. 30. Instead, the
thread shafts 240A', 240B' are separated. The standoff 196' can still be
employed to provide the floating PCB 86 features discussed above. Also
note that the standoffs 196, 196' configured to allow a PCB to float can
also be provided for the standoffs 196, 196' provided to install any
other components of the HEU 14, including but not limited to the downlink
BIC 54 and the uplink BIC 56. Further, the design of the bodies 199, 199'
may include a hexagonal outer surface over the entire length of the
bodies 199, 199'.

[0105] FIGS. 32A and 32B are side cross-sectional views of an alternative
standoff 250 that can be employed to secure the OIC PCBs 86 and provide
one of the OIC PCBs 86 as a floating PCB. The alternative standoff 250
may be employed to secure the OIC PCBs 86 when the shield plates 95A, 95B
are installed, as illustrated in FIG. 26B. In this regard, one standoff
252 is configured to be disposed within another standoff 254. The first
standoff 252 contains a thread shaft 256 that is configured to receive a
fastener to secure a shield plate 95 to the standoff 252 and the OIM 84.
The standoff 252 contains a threaded member 255 that is configured to be
secured to a threaded shaft 257 disposed in the standoff 254. The
standoff 254 contains a collar 258 similar to the collar 220, as
described above in FIGS. 28-29B, that surrounds the threaded shaft 257
and is configured to be received inside an opening of an OIC PCB 86
having a greater inner diameter than the outer diameter OD3 of the
collar 258. This allows an OIC PCB 86 disposed on the collar 258 to float
with respect to another OIC PCB 86 secured to a thread shaft 260 of the
standoff 254. The standoff 254 has a collar 262 having an outer diameter
OD4 that is configured to be received in an opening in an OIC PCB 86
that does not allow float.

[0106] Another alignment feature provided by the embodiments disclosed
herein is alignment assistance provided by the digital connectors
disposed in the midplane interface card 58 that accept digital
connections from the OICs 60, the downlink BIC 54, and the uplink BIC 56.
As previously discussed and illustrated, digital connectors, including
connectors 94B, disposed in the midplane interface card 58 receive
complementary digital connectors 194 from the OICs 60, the downlink BIC
54, and the uplink BIC 56 when inserted into the enclosure 72. The OICs
60, the downlink BIC 54, and the uplink BIC 56 are designed such that
their digital connections are first made to corresponding digital
connectors disposed in the midplane interface card 58 when inserted into
the enclosure 72 before their RF connections are made to RF connectors
disposed on the midplane interface card 58. In this manner, these digital
connections assist in aligning the OICs 60, the downlink BIC 54, and the
uplink BIC 56 in the X and Y directions with regard to the midplane
interface card 58.

[0107] In this regard, FIG. 33 illustrates a side view of the assembly 70
showing a digital connector 194 from an OIC 60 being connected to a
complementary connector 94B disposed in the midplane interface card 58.
As illustrated therein, the digital connector 194 disposed in the OIC 60
is designed such that the digital connector 194 makes a connection with
the complementary connector 94B in the midplane interface card 58 before
an RF connector 195 disposed in the OIC 60 makes a connection with the
complementary RF connector 94C disposed in the midplane interface card
58. In this regard, when the digital connector 194 begins to connect with
the complementary connector 94B, the digital connector 194 aligns with
the complementary connector 94B. The end of the RF connector 195 in the
OIC 60 is still a distance D away from the complementary RF connector
94C. In one non-limiting embodiment, the distance D may be 0.084 inches.
Because the digital connectors 194 on the OICs 60 are in a fixed
relationship to the RF connectors 195 provided therein in this
embodiment, alignment of the digital connectors 194 also provides
alignment of the RF connectors 195 of the OICs 60 to the complementary RF
connectors 94C disposed in the midplane interface card 58 as well. Thus,
as the digital connector 194 is fully inserted in the complementary
connector 94B, the RF connector 195 will be aligned with the
complementary RF connector 94C when disposed therein. Alignment of the RF
connector 195 may be important to ensure efficient transfer of RF
signals. This feature may also be beneficial if the RF connections
require greater precision in alignment than the digital connections. The
same alignment feature can be provided for the downlink BIC 54 and uplink
BIC 56.

[0108] As previously discussed and illustrated in FIG. 4, the OIM plate 88
provides support for the connectors 90 and for attaching the OICs 60 to
the OIM plate 88 to provide alignment of the OICs 60 when inserted into
the enclosure 72. An OIM plate 88 is provided to assist in coupling a
pair of OICs 60 together to form the OIM 84. The OIM plate 88 serves to
support the OICs 60 and contributes to the alignment the OICs 60 for
proper insertion into and attachment to the enclosure 72, which in turn
assists in providing a proper and aligned connection of the OICs 60 to
the midplane interface card 58. In this regard, as illustrated in FIG.
34, one feature that can be provided in the OIM 84 to allow the OIM plate
88 to be provided in embodiments disclosed herein is to provide an OIC
PCB 86 that extends beyond receiver optical sub-assemblies (ROSAs) and
transmitter optical sub-assemblies (TOSAs) provided in the OIC 60.

[0109] As illustrated in FIG. 34, a top perspective view of the OIM 84 is
provided illustrating the extension of OIC PCBs 86 beyond transmitter
optical sub-assemblies (TOSAs) 262 and receiver optical sub-assemblies
(ROSAs) 260. The TOSAs 262 and ROSAs 260 are connected via optical fibers
263, 265 to the connectors 90 that extend through the OIM plate 88 to
allow connections to be made thereto. By extending the OIC PCBs beyond
the TOSAs 262 and ROSAs 260, the OIM plate 88 can be secured to the OIC
PCBs 86 without interfering with the TOSAs 262 and ROSAs 260. In this
embodiment, the TOSAs 262 and ROSAs 260 are mounted or positioned on an
end of a PCB to transmit and/or receive optical signals interfaced with
electrical signal components disposed in the OIC PCB 86. Mounting or
positioning of TOSAs 262 and ROSAs 260 on the end of a PCB may limit the
length of exposed, unshielded wire extensions between the TOSAs 262 and
ROSAs 260 and printed traces on the PCB. This provides for signal
integrity of the signals after conversion to electrical signals.

[0110] Thus, a sufficient space is provided to allow for the TOSAs 262 and
ROSAs 260 to extend beyond an end of a PCB. In this regard, openings 264,
266 are disposed in the OIC PCB 86 in this embodiment. The openings 264,
266 allow the TOSAs 262 and ROSAs 260 to be disposed in the OIC PCB 86
without the TOSAs 262 and ROSAs 260 extending beyond an end 268 of the
OIC PCB 86 where the OIM plate 84 is disposed. Thus, the openings 264,
266 allow the TOSAs 262 and ROSAs 260 to be disposed at an end 270 of the
PCB where the openings 264, 266 start, but not at the end 268 of the OIC
PCB 86 where the OIM plate 88 is located. In this manner, space is
provided for the TOSAs 262 and ROSAs 260 such that they do not interfere
with or prevent the OIM plate 88 from being disposed at the end 268 of
the OIC PCB 86.

[0111] It may also be desired to provide a cooling system for the assembly
70. The components installed in the assembly 70, including the downlink
BIC 54, the uplink BIC 56, the HEC 42, and the OICs 60 generate heat.
Performance of these components may be affected if the temperature due to
the generated heat from the components is not kept below a threshold
temperature. In this regard, FIGS. 35 and 36 illustrate the assembly 70
and enclosure 72 of FIG. 3 with an optional cooling fan 280 installed
therein to provide cooling of components installed in the enclosure 72.
View of the cooling fan 280 is obscured by a cooling fan protector plate
282 in front perspective view of the assembly 70 in FIG. 35; however,
FIG. 36 illustrates a side cross-sectional view of the assembly 70 and
enclosure 72 showing the cooling fan 280 installed in the enclosure 72
behind the cooling fan protector plate 282 attached to the enclosure 72.
In this embodiment, cooling is provided by the cooling fan 280 taking air
into the enclosure 72 through openings 284 disposed in the cooling fan
protector plate 282 and drawing the air across the components in the
enclosure 72, as will be described in more detail below. The air may be
pushed through the rear of the enclosure 72 through an air outlet, as
illustrated in FIG. 36. For example, the cooling fan 280 may be rated to
direct air at a flow rate of sixty (60) cubic feet per minute (CFM) or
any other rating desired.

[0112] With continuing reference to FIG. 36, a lower plenum 286 and an
upper plenum 288 is provided in the enclosure 72. The lower plenum 286 is
provided to direct air pulled in the enclosure 72 by the cooling fan 280
initially to the bottom of the enclosure 72 to allow the air to then be
directed upward through OICs 60 installed in the enclosure 72 and to the
upper plenum 288 to be directed to the rear and outside of the enclosure
72. Passing air across the OICs 60 cools the OICs 60. This air flow
design is further illustrated in the air flow diagram of FIG. 37. In this
regard, with reference to FIG. 36, a fan duct 290 is provided behind the
cooling fan 280 to direct air drawn into the enclosure 72 by the cooling
fan 280. A plate 292 is installed in the fan duct 290 to direct air flow
down from the fan duct 290 into the lower plenum 286. The air from the
lower plenum 286 passes through openings disposed in a lower plenum plate
294 and then passes through the openings disposed between OICs 60 wherein
the air then passes through openings 296 disposed in an upper plenum
plate 298, as illustrated in FIG. 38. In this manner, air is directed
across the OICs 60 to provide cooling of the OICs 60. Air then entering
into the upper plenum 288 is free to exit from the enclosure 72, as
illustrated in FIG. 36. The upper plenum 288 is open to the outside of
the enclosure 72 through the rear of the enclosure 72, as illustrated in
FIGS. 36 and 37 and in FIG. 39.

[0113] Further, as illustrated in FIGS. 40 and 41, openings 300 and 302
can also be disposed in the upper plenum plate 298 above the uplink BIC
56 and in the downlink BIC 54 to provide further movement of air for
cooling purposes. These openings 300, 302 allow some of the air flowing
into the enclosure 72 from the cooling fan 280 to be drawn from the lower
plenum 286 into the downlink BIC 54 and then into the uplink BIC 56 via
openings 302. Air can then be directed from the uplink BIC 56 through
openings 300 and into the upper plenum 288 outside of the enclosure 72.

[0114] Further, as illustrated in FIGS. 36, 39, and 41 an optional second
cooling fan 301 is provided below the upper plenum plate 298. In this
manner, some of the air from the enclosure 72 is drawn through the power
supply 59 by the second cooling fan 301 to provide cooling of the power
supply 59. For example, the second cooling fan 301 may be rated to direct
air at a flow rate of thirteen (13) cubic feet per minute (CFM) or any
other rating desired.

[0115] Many modifications and other embodiments set forth herein will come
to mind to one skilled in the art to which the embodiments pertain having
the benefit of the teachings presented in the foregoing descriptions and
the associated drawings. Therefore, it is to be understood that the
description and claims are not to be limited to the specific embodiments
disclosed and that modifications and other embodiments are intended to be
included within the scope of the appended claims. For example, the
embodiments disclosed herein can be employed for any type of distributed
antenna system, whether such includes optical fiber or not.

[0116] It is intended that the embodiments cover the modifications and
variations of the embodiments provided they come within the scope of the
appended claims and their equivalents. Although specific terms are
employed herein, they are used in a generic and descriptive sense only
and not for purposes of limitation.